PDA

View Full Version : 401 pitch instability issue



WESTLOWER
11-01-2018, 22:59
Garrard 401 pitch instability issue... Cry for advice!!
Can anyone shed some light on why the strobe should
Stray left and then right and will not stay still?

Making good piano ballads sound a bit Les Dawson ish
Thoughts?!

Primalsea
11-01-2018, 23:14
The strobe indicators on my 401 are not perfectly spaced, so there is some minor shifting back and forth. Also speed stability only really becomes rock solid after about 45, when everything has warmed up.

If you are having a major speed stability issue it could be a few things. Has the rubber idler wheel perished? Also the motor pulley can become polished over time which stops the idler wheel have the correct traction. Wiping the inside of the platter with some IPA can help too.

Also you can have bearing issues, I tend to oil mine every few months and every few years strip it down and clean it. Also I check all the springs as some of these tension the idler wheel against the pulley and he platter.

WESTLOWER
11-01-2018, 23:20
The strobe indicators on my 401 are not perfectly spaced, so there is some minor shifting back and forth. Also speed stability only really becomes rock solid after about 45, when everything has warmed up.

If you are having a major speed stability issue it could be a few things. Has the rubber idler wheel perished? Also the motor pulley can become polished over time which stops the idler wheel have the correct traction. Wiping the inside of the platter with some IPA can help too.

Also you can have bearing issues, I tend to oil mine every few months and every few years strip it down and clean it. Also I check all the springs as some of these tension the idler wheel against the pulley and he platter.
Thanks Paul appreciate the advice

Beobloke
12-01-2018, 13:01
Also, make sure the eddy current brake disc isn't warped or damaged. It must be perfectly flat to do its job properly.

WESTLOWER
12-01-2018, 13:04
Also, make sure the eddy current brake disc isn't warped or damaged. It must be perfectly flat to do its job properly.

will do. cheers

A.Grail
13-01-2018, 19:05
Is the pulley aligned correctly - With the platter removed get down the eye lever with the running face of the idler wheel with the unit on. Does the idler wheel contact centrally on each step of the pulley or is it fouling the step above?

With the platter removed spin the idler wheel, does is spin freely or does it stop abruptly?

- It is worth removing the idler wheel, cleaning the bushes and re oiling

- Outside of general cleaning as mentioned above if the pulsing (Speed fluctuations) continue it may be a motor coil issue

WESTLOWER
13-01-2018, 20:09
Thank you matt I'll check it out

WESTLOWER
14-01-2018, 00:08
Matt definitely the pulley adjustment... rock solid now! Thank you